Clips in the general nature of those to which this invention relates are exemplified in patent documents WO 02/076836 and 99/19223, of common inventorship herewith. In general, such clips comprise a pair of axially elongated jaws which are hinged together adjacent one axial end thereof to permit them to swing between a closed position in which the jaws are mutually confronting substantially along their length, and an open position, and a latch disposed adjacent the opposed axial end for releasably retaining the jaws closed about a bag or the like as desired.
The bags with which such clips may find use may vary considerably in their characteristics, for example from thin, single ply polymer film to thick, multi-ply paper. Although clips of several different sizes are available, and a user will normally select a clip having an appropriate size, variations in the bag thickness for any given size of bag are such that they will have a limited range of use.
While bag clips are not normally manufactured to be disposable items, particularly where they are intended for use in larger size bags having a capacity of about 50 kg (about 100 lbs) or more, they are none-the-less required to be inexpensive, and accordingly any improvements should not incur any significant change in cost, thereby effectively precluding highly engineered solutions.
A further problem with bag clips, particularly of the larger sizes, is that the hinge elements are exposed to substantial levering forces, which tend to spring the hinge elements apart where these are of a type using a hinge pin, and skew the jaws.
Known bag clips often use a box hinge comprising three generally orthogonally connected walls forming an axially aligned channel associated with one jaw, having bearing openings in the facing walls of the channel. The other jaw may be provided with a hinge bearing unitarily formed therewith, which snaps into the bearing openings when the channel walls are resiliently deformed. Although this type of hinge is cost effective, it is prone to separating under heavy loads, due either to the use of cup and ball type bearings which engender a wedging apart of the cheeks under the influence of loading forces, or due to the channel walls being too easily deformed in a resilient manner. To overcome these tendencies, hinge pins must be used to the exclusion of cup and ball arrangements, and the channel walls of the hinge may be made substantially more rigid, for example by increasing the thickness thereof, and/or by providing a fourth wall, which interconnects the channel walls substantially along the height of these walls. However, this has heretofore prevented the snap engagement of the fixed hinge pin into the bearing openings, and it has been necessary to use a separately formed hinge pin, thereby increasing manufacturing costs, or to use a hook-together arrangement which reduces the integrity of the hinge.
It is an object of this invention to provide improved bag clips that may more readily accommodate different sizes of bags.
It is another object of this invention to provide bag clips that are economic to produce and easily adjustable.
It is yet another object of this invention to provide adjustable bag clips that are capable of resisting normal forces to which they may be exposed.
It is still another object of this invention to provide bag clips with an economic, two piece hinge structure that is not easily separable under heavy loads.